//  https://www.luogu.com.cn/problem/P1434

#include<iostream>
using namespace std;
const int N = 110;
int f[N][N], a[N][N];
int n, m;
int dx[] = { 0,0,1,-1 };
int dy[] = { 1,-1,0,0 };

int dfs(int i, int j)
{
    if (f[i][j]) return f[i][j];

    int len = 1;
    for (int k = 0;k < 4;k++) {
        int x = i + dx[k], y = j + dy[k];
        if (x < 1 || x > n || y < 1 || y > m) continue;
        if (a[x][y] >= a[i][j]) continue;
        len = max(len, dfs(x, y) + 1);
    }
    return f[i][j] = len;
}
int main()
{
    cin >> n >> m;
    for (int i = 1;i <= n;i++)
        for (int j = 1;j <= m;j++)
            cin >> a[i][j];

    int ret = 0;
    for (int i = 1;i <= n;i++)
        for (int j = 1;j <= m;j++)
            ret = max(dfs(i, j), ret);

    cout << ret << endl;
    return 0;
}
